1. Field of the Invention
The present invention relates to an apparatus for fabricating liquid crystal display (LCD) panels and to a method of fabricating LCD panels. More particularly, the present invention relates to an apparatus, used for fabricating LCD panels, that has a simplified structure and reduces the length of a production line, in addition to, a method of fabricating LCD panels.
2. Discussion of the Related Art
Generally, LCD devices display images by controlling light transmittance characteristics of an array of pixels in accordance with data signals, derived from image information, applied to the pixels. A typical LCD device includes a unit LCD panel having a plurality of pixels arranged in a matrix pattern, and gate and data driving units for driving the pixels.
The LCD panel typically includes a color filter substrate and a thin film transistor (TFT) array substrate attached to each other and separated from each other by a cell-gap. A liquid crystal layer is also formed within the cell-gap, between the color filter and TFT array substrates.
The color filter substrate supports a common electrode while the TFT array substrate typically supports a plurality of data lines transmitting data signals from the data driving unit to the pixels, a plurality of gate lines transmitting scan signals from the gate driving unit to the pixels, and a plurality of TFTs arranged within each of the pixels. The gate and data lines are generally arranged orthogonally to each other and, where they cross, define the pixels. In response to scan signals sequentially supplied by the gate driver, the TFTs switch data signals transmitted by the data driving unit from the data lines to corresponding pixel electrodes.
Thus, when data and reference signals are applied to the pixel and common electrodes, respectively, an electric field is generated within the liquid crystal layer. Due to anisotropic dielectric properties of molecules within the liquid crystal layer, the generated electric field rotates liquid crystal molecules between the common electrodes and the pixel electrodes. When the liquid crystal molecules rotate, the light transmittance characteristics of the pixel change. Thus, by controlling the magnitude of the generated electric field with the data and reference signals, the plurality of pixels may be controlled to display images.
FIG. 1 illustrates a plan view of a related art LCD panel.
Referring to FIG. 1, the related art LCD panel 100 includes an image display unit 113 having a plurality of pixels arranged in a matrix pattern, a gate pad unit 114 connected to gate lines of the image display unit 113, and a data pad unit 115 connected to data lines of the image display unit 113.
The image display unit 113 of the LCD panel 100 includes a TFT array substrate 101 and a color filter array substrate 102. The TFT array substrate 101 supports gate and data lines that cross each other to define pixels, pixel electrodes formed within the pixels, and TFTs arranged at crossings of the gate and data lines and connected to corresponding pixel electrodes for driving the pixel electrodes. A protecting film (not shown) is formed over the entire surface of the TFT array substrate 101 to protect the electrodes and the TFTs.
The gate pad unit 114 and the data pad unit 115 are formed at edges of the TFT array substrate 101 that are not overlapped by the color filter substrate 102. Accordingly, the gate pad unit 114 transmits scan signals, supplied by a gate driving unit (not shown), to the gate lines and the data pad unit 115 transmits image information, supplied by a data driving unit (not shown), to the data lines.
The color filter substrate 102 supports a black matrix defining cell regions, a plurality of color filters separated by the cell regions, and common transparent electrodes opposing the pixel electrodes.
The thin film transistor array substrate 101 and the color filter substrate 102 are joined to, and spaced apart from, each other via a seal pattern structure 116 formed at the periphery of the image display unit 113 to define a cell-gap. Uniformity of the cell gap is maintained by a spacer structure (not shown) and a liquid crystal layer is formed within the cell gap.
Recently, a process has been developed that facilitates the simultaneous fabrication of a plurality of the LCD panels (such as those shown in FIG. 1) and thereby increases the production yield of such LCD panels. Typically, a plurality of TFT array substrates are formed on a first base substrate, larger than each individual TFT array substrate, a plurality of color filter substrates are formed on a second base substrate, larger than each individual color filter substrate; the first and second base substrates are joined to each other via the sealant material; and the joined first and second base substrates are cut and processed to form individual (i.e., unit) LCD panels.
FIG. 2 schematically illustrates a related art apparatus used to fabricate unit LCD panels.
Referring to FIG. 2, the related art apparatus typically includes an attaching unit 210 for joining the first and second base substrates; a cutting unit 220 for cutting the joined first and second base substrates to form separated unit LCD panels; a first loading unit 230 for loading the unit LCD panels; a cut section checking unit 240 for checking cut sections of the loaded unit LCD panels; a first unloading unit 250 for unloading the checked unit LCD panels; a robot 260 for transferring the unloaded unit LCD panels from the first unloading unit 250; an aligning unit 270 for aligning the transferred unit LCD panels; a grinding unit 280 for grinding edges of the aligned unit LCD panels; and a second unloading unit 290 for unloading the ground unit LCD panels.
As shown above, the cut section checking unit 240 and the grinding unit 280 are physically separate units. Therefore, each unit requires its own loading and unloading units to ensure that unit LCD panels are properly loaded into, and removed from, the cut section checking and grinding units 240 and 280. Because each of the cut section checking and grinding units 240 and 280 require their own loading/unloading units, they also require their own loading/unloading and transferring procedures.
Specifically, the checking procedure employed to check the cut sections of the unit LCD panels involves operating the first loading unit 230 to load the separated unit LCD panels into the cut section checking unit 240, operating the cut section checking unit 240 to check the cut sections of the loaded unit LCD panels, and operating the first unloading unit 250 to unload the checked unit LCD panels. Similarly, the grinding procedure employed to grind the edges of the checked unit LCD panels involves operating the robot 260 to transfer the checked unit LCD panels into the aligning unit 270, operating the aligning unit 270 to align the loaded unit LCD panels, operating the grinding unit 280 to grind the edges of the aligned unit LCD panels, and operating the second unloading unit 290 to unload the ground unit LCD panels. Further, the unit LCD panels must be transferred between the first loading unit 230 and the cut section checking unit 240, between the cut section checking unit 240 and the first unloading unit 250, between the aligning unit 270 and the grinding unit 280, and between the grinding unit 280 and the second unloading unit 290.
As is evident, the time required to complete fabrication of a unit LCD panel, as well as the amount of space required by the related art apparatus and using the related art apparatus described above, can be excessive. Further, use of the related art apparatus described above can increase the cost of fabricating the unit LCD panels, increase the cost of maintaining the fabrication equipment, and decrease the efficiency with which the unit LCD panels are fabricated.